1. Field of Invention
The present invention relates generally to the field of communications systems, and more particularly in one exemplary aspect to storing and distributing access control clients to devices.
2. Description of Related Technology
Access control is required for secure communication in most prior art wireless radio communication systems. As an example, one simple access control scheme might comprise: (i) verifying the identity of a communicating party, and (ii) granting a level of access commensurate with the verified identity. Within the context of an exemplary cellular system (e.g., Universal Mobile Telecommunications System (UMTS)), access control is governed by an access control client, referred to as a Universal Subscriber Identity Module (USIM) executing on a physical Universal Integrated Circuit Card (UICC). The USIM access control client authenticates the subscriber to the UMTS cellular network. After successful authentication, the subscriber is allowed access to the cellular network. As used hereinafter, the term “access control client” refers generally to a logical entity, either embodied within hardware or software, suited for controlling access of a first device to a network. Common examples of access control clients include the aforementioned USIM, CDMA Subscriber Identification Modules (CAM), IP Multimedia Services Identity Module (ISIM), Subscriber Identity Modules (SIM), Removable User Identity Modules (RUIM), etc.
Traditionally; the USIM (or more generally “SIM”) performs the well known Authentication and Key Agreement (AKA) procedure, which verifies and decrypts the applicable data and programs to ensure secure initialization. Specifically, the USIM must both. (i) successfully answer a remote challenge to prove its identity to the network operator, and (ii) issue a challenge to verify the identity of the network.
While traditional SIM solutions are embodied within a removable Integrated Circuit Card (ICC) (also referred to as a “SIM card”), incipient research by the Assignee hereof is directed to virtualizing SIM operation within a software client executing within the mobile device. Virtualized SIM operation can reduce device size, increase device functionality, and provide greater flexibility.
Unfortunately, virtualized SIM operation also presents multiple new challenges for network operators and device manufacturers. For example, traditional SIM cards are manufactured and guaranteed by a trusted SIM vendor. These traditional SIM cards execute a single secure version of software that has been permanently “burned” to the SIM card. Once burned, the card cannot be tampered with (without also destroying the SIM card).
In contrast, mobile devices are manufactured by a wide range of device manufacturers, and may execute software provided by multiple or even unknown third party software vendors. Additionally, mobile devices are frequently “patched” with software, which can both fix existing bugs, and introduce new ones. Any software is susceptible to corruption, sabotage, and/or misuse. Moreover, while physical SIM cards are very difficult to replicate, software can be readily copied, multiplied, etc. Since each SIM represents a contracted for amount of access to finite network resources, illicit use of a virtualized SIM can greatly impact network operation and user experience.
Accordingly, new solutions are needed for providing protections and properties for virtualized SIMs that are generally analogous to those of traditional “hard” SIMs. More generally, improved solutions are needed for storing and distributing virtualized access control clients. Ideally, such solutions should provide the benefits of traditional access control client operation, with the added capabilities of virtualized operation.